In processing a great amount of data and messages, a computer, server or workstation needs sufficient memory space. Hard disc or other data storage devices are to provide such a memory space wherein portable hard disc not only can facilitate users to expand memory capacity but also is convenient for being carried by users. For example, RAID box (Redundant Array of Independent Disc Box) can efficiently utilize multiple hard discs thereof since each of the hard discs can share and duplicate data in other hard discs. The hard discs of the RAID box for the convenience of users are usually designed to be portable. Each of the hard discs is adopted in a drawer and the drawer is slidably received in a case. Nonetheless, when a data processing device such as a server is processing data, a user may, based on negligence or other reasons, improperly withdraw the drawer from the case and result in that data under process cannot be timely saved in the hard disc in the drawer and thus are lost. A user also may not notice that the drawer is not properly received in the case and hence cannot save the data processed.
To overcome these problems, in the conventional art, a switch is installed at the drawer, a connector such as a plug is installed at the rear of the drawer, and another connector such as a socket that can incorporate with the plug is installed at the case in the correspondent location wherein the switch is to control the plug in determining whether the plug connects with the socket or not through a wire arrangement. When the switch is at the KEY ON status, the plug at the rear of the drawer connects the socket at the case, which represents that the drawer is properly received within the case. When the switch is at the KEY OFF status, the plug at the rear of the drawer disconnects the socket at the case, which represents that the drawer is not properly received within the case and the drawer is ready for being taken out from the case. The server or computer connected to the RAID box through a detecting device can detect whether the drawer is properly received within the case and take some emergency measures such as immediately saving data or information before the drawer is taken out from the case of the RAID box and data or information is lost.
However, the conventional art has some problems, which causes inconvenience and inefficiency to users. For example, the plug and socket sometimes cannot be precisely connected because the plug and the socket are designed to be mechanically connected therebetween. Besides, there are some further disadvantages in the conventional art: (i) the additionally installed connectors (plug and socket) increase the cost of manufacture; (ii) to install the additional connectors, the manufacture has to modify the locations of the original connectors; (iii) it is difficult to install the connector socket at the inside bottom of the case; and (iv) it is difficult to make the wire arrangement for controlling the plug because the drawer is designed to be small and light and the space thereof is limited.
Therefore, an apparatus for a disc system that can overcome the problems existing in the prior art, especially to solve the problems of inconveniency and difficulty caused by the additional connectors and wire arrangement, is needed.